Dust guard for journal bearings



Patented July 29, 1941 'UNH'EED STATES PAT EN 'i 0i E l CE fDUS'I GUARDFOR JOURNAL BEARINGS Marcelll/eunier, Levallois-Perret, France 2 Claims.

This invention relates to dust guards forrjournal bearings, includingjournal boxes for the axles of railroad vehicles.

While dust guards have been heretofore made comprising rigid orsemi-rigid wall portions used, with or without an axle engaging sealingring, and which depend for their eiciencyupon elastic pressure tomaintain a dustproof jointiabout the axle, nevertheless, previousdevices, `so far as is known, are open to the objection that they causethe concentration of too much `friction on the shaft; and, in manycases, the rotation of the axle or shaft tends to increase such frictiondue to the wedging or jamming action incident to the relative movementofthe par-ts formingthe wall or plate portion of the guard.Consequently, there is relatively quick Wear and tear of the sealingelement as well as of the shaft itself where they engage, especially ifmineral dust adheres to or becomes imbedded in the material forming theseal. On the other hand, it has also been diflcult to obtain a tight andsatisfactory closure, because of the joints occurringbetween thedifferent parts which generally form the shield or guard, or because of4the play or tolerance which must be provided to allow the relativemovement of the shaft in respect to the bearing, as, for instance, inthe case of journal boxes used on railroad vehicles.

Accordingly, the present invention has in view a simple and practicalconstruction which remedles the disadvantages set forth, and to that endthe shaft is surrounded where `it emerges from the bearing by supple andyielding means in the form of a split collar or ring arranged to form anannular joint which is held in position by at least one element of asectional plate or disk arranged to continuously-exert pressureconcentrically thereon. This assures the holding of the annular elementor collar properly around the shaft by pressure while at the same timethe plate or disk is held between or against the Walls of the bearing orbox to prevent lateral shifting of the collar, that is, shiftingparallel -to the axis of the shaft or axle.

A preferred and practical embodiment of the invention is shown in theaccompanying drawing, in which:

Figure 1 is a partial sectional elevation of one form of construction.

Figure 2 is a detail perspective view of a portion of the split collar.

Figure 3 is a detail side elevation of the annular dust guard Wall orplate .comprising va plurality of segments having inner and outersections.

Figure 4 is a detail sectional view illustrating the ,use` of ashimplate to carry the abutment orstop `for engaging certain of the segmentsof the plate.

vFigure y5 is a `vertical sectional view of a modiedfform ofconstruction wherein the dust guard shown in Figure 1 is placed within acasing thereby to be handled as a unit for insertion in railway ,journalboxes now in use and having an integral dust vguard receiving pocket.-Figure' is a detail vertical sectional view illustrating a modificationshown in Figure vvl Wherein'two springs are used for radially pressingthe segments toward the sealing collar.

Similar reference `characters designate corresponding parts throughoutthe several figures of the, drawing. f

`In ,the-examplesshown by Figures l to 3,-!'0 indicates the extremityofthe Vjournal box of a lubricatingbearing, and, Il designates the shaftadapted to revolve'in the'bearing. Upon thebody ofthe box lthere isprovided aV hood i2, having a central holel' concentric to'the hole lllkof the Abodyof ,thebox. The saidhood yl2 is held in .position by thebol-ts l5.

Vlin its primary aspect, the relatively movable or self ,adjustingparts'of the dust guard are designated generally-as AA and B, the formervbeing inthe nature of asectional disk or plate and the latter'in formof a split and fiexible or yielding sealing collar.

MReferring first tothe circular or disk-likemember A, it will be seenfrom Figure l that it is 1ocated in the rchamber or space providedbetween thev body ofthe box Hl and the hood i2. Said memberconsists of aplurality ofrigid segments I6 each of which consists of two sections iland Aiivmade for example, of aluminum, held together by appropriatemeans, such as rivets or the like.' Each `inner section Il has Vat itsexternal periphery algroove i9 consisting of two inclined planes, andthe external periphery of each outer section I8 hasan inclined surface.2t forming a continuation of one of the wallsiof4 the groovefl 8.

'Upon their. interior periphery each -section 'l1 and I8has a circularrib 2|. intended tot into corresponding grooves 22 of thelsealing-collarB Whose ,body.2\3 may be of flat elongated crosssection and made of anysuitable material such as leather, rubber, rubber composition, or in:fact any substance having suflicient stamina and flexibility to conformcloselyfto the `outer. periphery ofthe axlell. A .l

In order to assure the necessary relative adjustability of the segmentsI6, while at the same time insuring complete dust tightness, one radialside edge of each section I8 is provided with a tongue 24 and the otherradial side edge is provided with a recess 25 of corresponding size.Thus, when the segments are assembled the tongue 24 of each section tsfreely into the recess 25 of the adjacent section, in mortise and tenonfashion, as shown in Figure 3.

The sections I1 are formed with straight radial side edges, and, as willbe apparent from Figure 3, they are so positioned angularly with regardto the sections I8 that they cover or cross the joint formed by themortise and tenon connections formed by the tongues 24 and recesses 25.In this manner a supple or flexible selfadjusting, and simultaneouslytight plate or dust excluding wall assemblage is obtained.

In order to obtain and maintain uniform tightness and relativecircumferential adjustment for the collar B forming the axle engagingpart of the guard, the two extremities of the body 23 are cut on matingmedial and transverse planes. Thus split, the adjacent ends of the ringare formed with laterally overlapping tongues 26, in such a manner thata tight joint permitting the necessary circumferential expansion andcontraction of the ring is possible, as shown in Figure 2.

The segments I6 are held yieldingly on the ring B about the shaft II bya helical ringshaped coil spring 21. As shown in Figure 1 this spring,which surrounds the four segments IE, has a diameter sufficient to restat one side upon the inclined surface I9-2Il while the other sideengages the wall of the body of the box I in such a manner that thelateral exterior face of the sections I8 are urged or pressed againstthe inner face of the wall of the hood I2, thus making a dust-proofvertical joint, and also holding the collar B against lateraldisplacement along the axle or shaft.

In order toprovide play necessary for the device to function so that thejoint between the shaft II and sealing collar B remains tight, even incase of wear and tear, the dimensions of the collar as well as of thesegments I6 are calculated in such a maner that, when these are onceassembled, sufficient tolerance or space is provided at the points 26mand 28 (Figs. 2 and 3), respectively, between the extremities of thecollar and the segments.

A lug 29 attached solidly to the wall of the body of the box I0 projectsinto the free space 28 between the extremities of the sections I1 of thesegments I6 thereby to form a stop against which one of the radial sidewalls of one of the sections I1 rests, corresponding to the direction ofthe rotation of the axle. The stop 29 is, of course, located close tothe end spaces or clearances 26a; of the ring B in order to permit thesaid ring to readily contract and seal the periphery of the axle.

The operation of the device shown in Figures l-3 is as follows:

The circular wall or disk A comprising the segments I6 is assembled uponthe`split collar B which surrounds the shaft I I, as shown in Figure 3,and said segments are elastically held in position by the helical spring21 surrounding their outer edges. As shown in Figure 1, the spring 21rests against the wall of the body of the box, and also rests upon theincline formed by the surfaces I9 and 20 of the sections I1 and I8 ofthe segments I6. Thus, the segments forming the plate or disk A areyieldingly pressed against the interior surface of the hood I2. Thisestablishes a closure preventing the passage of dust. On the other hand,as no space exists between the segments I6, or between the extremitiesof the collar B, the joint is tight at the point where the shaft IIleaves the box IU.

As may be readily understood, the rotation of the shaft I I tends to jamthe segments I 6 against each other, and, consequently, there is atendency to produce an undesirable friction between the sealing ring Band the shaft I I. In order to avoid this result, the stop or abutment29, located in the radial space 28 between certain of the side edges ofthe inner sections I1, rst, prevents axial displacement in the directionof rotation of all of the segments I6; and, secondly, permits movementwhich tends to loosen the elements above the stop, thereby tending totemporarily counteract the action of the spring 21. In this way, thereis simultaneously obtained a tight joint and an appreciable reduction offriction.

A slight modification of the invention is shown in Figure 4 wherein thedust guard construction heretofore described, and consisting of thecircular wall or disk A including a plurality of segments composed ofthe sections I1 and I8, the collar B, and spring 21, may be located in achamber 30 formed by the hood I2 and an annular shim plate or similarpart 3I fltted to the interior side wall of the box. In this case theinner surface of the shim plate carries the stop or abutment 29. Thisform of construction permits assembling the whole dust shield in advanceand threading it upon the shaft II to be covered by the hood I2, asindicated.

Figure 5 illustrates a construction which makes possible the use of thefeatures heretofore described in axle boxes of railroad cars, now inuse. As will be observed from this figure, a dust guard made inaccordance with the present invention may be placed in the chamber 32which was formed with the body of the box ID when it was made. That isto say, the complete assembly of parts, as described in Figure l, may beplaced in an annular casing 33 and handled as a unit. This casing has aninclined surface 34 at its periphery, and the helical spring 35 reststhereon. This spring has one side or portion resting against the wall 36of the chamber 32 and thus presses the casing 33 against the oppositewall 31, thereby establishing a joint which prevents the passage ofdust.

In the modified construction shown in Figure 6 the principles ofconstruction are the same with respect to the body 23 of the splitcollar B surrounding the shaft, but, the peripheral edges of thesections I1 and I9 of the segments are each inclined toward their outerfaces, starting from the medial plane of the dust shield. In this case,two springs 21' are provided, each of which rests upon one of the innersurfaces of the chamber enclosing the dust shield and also upon one ofthe inclined peripheral edges of the sections I1 and I8. While in Figurel the desired lateral tightness is obtained due to the spring 21pressing one face of the dust shield against the inner wall of the hoodI2; nevertheless, in this construction, the springs 21' themselves forma dual dust barrier. This construction also provides a completely tightclosure for the bearing, permitting without damage, all of the necessaryrelative play of the shaft I I with respect to the body of the box III.

In order to protect the springs 21, 21 and 35, stiff grease may beintroduced into the hood which shelters the spring. Also, it Will beapparent that in place of the spring, any other elastic element, such asbands or rings of rubber or their equivalent, may be used.

Moreover, to avoid the angular displacement o1' the sealing collar B inrespect to the segments l of the circular dust guard Wall, suitablestops or abutments may be provided upon the segments themselves, saidstops coming in Contact with a portion of the box housing when theassembly is complete, or, as a further alternative the sealing ring maybe attached permanently to one of the segments I6.

Instead of making the outer edges of the segments on the true arc of acircle they may have a diierent curvature in such a Way to produce, forexample, a body of general oval form, with a circular central holecooperating with the sealing ring.

Without further description it is thought that the features andadvantages of the invention may be readily understood, and it will, ofcourse, be apparent that changes may be resorted to within the scope ofthe appended claims.

I claim:

1. In a dust guard for journal boxes, the combination with an axle and ahousing having laterally spaced walls, of a flexible split sealingcollar on the shaft and having a plurality of grooves therein, anannular plate having a plurality of segments arranged concentricallyabout the collar, said segments each comprising inner and outer sectionshaving disalined radial side edges whereby the joints in the platebetween the segments are masked respectively by the inner and outersections, rib-s on each of said sections of the segments formingcontinuous tongues adapted to enter the grooves on the collar, saidsegments each having its outer edge bevelled to face one of said walls,and an annular elastic element circumferentially engaging the plate andtending to move the segments thereof radially into contact with thecollar, said elastic means compris- .ing an endless coiled compressionspring engaging the bevelled edges and the Wall toward which they face.

2. In a dust guard for journal boxes, the combination with an axle and ahousing having laterally spaced walls, of a flexible split sealingcollar on the shaft, a casing having opposite side Walls and an inclinedperipheral edge wall, said casing being located between the spaced Wallsof the housing, an annular elastic element having a portion bearingagainst one side wall of the housing and the edge wall of the casingthereby to shift the casing toward the opposite side wall of thehousing, a dust guard plate comprising a plurality of segments adaptedfor relative radial movement toward the sealing collar, said segmentshaving their peripheral edges bevelled to face the casing Wall adjacentthe housing wall against which said elastic element bears, and anelastic member surrounding the periphery of the plate simultaneously topress all the segments toward the sealing collar, said last elasticelement bearing against the bevelled edges and said casing wall.

MARCEL MEUNIER.

